1. Field of the Invention
A method of producing electrical coil units, particularly for ignition apparatus.
2. Prior Art
In certain embodiments of capacitive ignition systems used in conjunction with ignition apparatus of the flywheel type, the ignition transformer and charging coil are placed on one and the same leg of an iron core. A typical example of such embodiment is described in U.S. Pat. No. 4,036,201. Apart from the windings mentioned there, there is often also a control winding or trigger winding on the same core leg. With such an arrangement, there is consequently obtained a coil unit for mounting directly onto the core leg in question.
In usual cases, the secondary winding of the ignition transformer is wound with one wire size on a coil bobbin or as a self supporting unit, and the charging coil is wound with a fairly similar wire size on another coil bobbin or as a further self supporting unit. From the production-winding aspect, it is extremely impractical to work with several wire sizes. Modern wire winding machines can indeed be controlled for both automatic connection to terminal pins and winding wire on a bobbin, but if several different wire sizes are to be wound on one and the same bobbin, it will be necessary either to put the bobbin into another winding machine with other wire sizes or to change the wire stock coil. These practices result in cost-consuming downtime, particularly in connection with large manufacturing orders.